The need to study dynamic processes in intact small animal models of disease has stimulated the development of high resolution multi-modality imaging methods that provide not only functional but also anatomical information. Photoacoustic imaging for biomedical applications has shown tremendous growth in the last decade due to its applicability to a spectrum of research topics such as oncology, brain imaging and nanoparticle research. Based on the concept of light in and sound out, photoacoustic imaging capitalizes on the rapid thermoelastic expansion of tissue upon absorption of pulsed laser energy. This thermoelastic expansion results in the generation of a wide band ultrasound wave which then can be detected with a transducer that converts the mechanical acoustic wave into electrical signals. When coupled with ultrasound, photoacoustic imaging can simultaneously provide anatomical and functional data. Photoacoutstic imaging occupies a void in molecular imaging by providing high optical contrast images at microscale resolution and at a reasonable penetration depth, therefore light absorbing structures deep inside tissues can be detected and visualized with resolutions far superior to pure optical methods. We are requesting funds to purchase a high-resolution photoacoustic system, Vevo LAZR (VisualSonics, Inc.), equipped with optical and acoustic components and analysis software. The addition of this photoacoustic system will strengthen both ongoing work in oncology, pharmaceutical sciences, engineering, neurosciences, and genetic medicine by current users of the USC Molecular Imaging Center, as well as greatly enhance the ability of the Center to support new research in liver disease, cardiology, pathology, developmental biology and nanoparticle research. We have gathered 14 NIH funded users (10 major users and 4 minor users) with research disciplines in alcohol/drug induced liver disease, engineering, dentistry, cardiology, oncology and pharmacy to support our current S10 application. This system, coupled with increasingly sophisticated mouse models that recapitulate human disease pathology, is fueling a revolution in the investigation of disease and normal developmental processes in vivo. The acquisition of the photoacoustics system will complement and support the research revolution towards personalized medicine.